page_title: Inflow (meteorology)
section_title: Thunderstorms
hierarchical_section_title: Inflow (meteorology) / Thunderstorms
caption_attribution_description: side view of a supercell thunderstorm
context_page_description: Inflow is the flow of a fluid into a large collection of that fluid. Within meteorology, inflow normally refers to the influx of warmth and moisture from air within the Earth's atmosphere into storm systems. Extratropical cyclones are fed by inflow focused along their cold front and warm fronts. Tropical cyclones require a large inflow of warmth and moisture from warm oceans in order to develop significantly, mainly within the lowest 1 kilometre of the atmosphere. Once the flow of warm and moist air is cut off from thunderstorms and their associated tornadoes, normally by the thunderstorm's own rain-cooled outflow boundary, the storms begin to dissipate. Rear inflow jets behind squall lines act to erode the broad rain shield behind the squall line, and accelerate its forward motion.
context_section_description: The inflow into a thunderstorm, or complex of thunderstorms, is the circulation of warm and humid air ahead of a trigger convergence zone such as a cold front. This airmass is uplifted by the trigger and form convective clouds. Later, cool air carried to the ground by thunderstorm downdraft, cuts off the inflow of the thunderstorm, destroying its updraft and causing its dissipation.
  Tornadoes, which form within stronger thunderstorms, grow until they reach their mature stage. This is when the rear flank downdraft of the thunderstorm, fed by rain-cooled air, begins to wrap around the tornado, cutting off the inflow of warm air which previously fed the tornado.
  Inflow can originate from mid-levels of the atmosphere too. When thunderstorms are able to organize into squall lines, a feature known as a rear inflow jet develops to the south of the mid-level circulation associated with its northern bookend vortex. This leads to an erosion of rain within the broad rain shield behind the squall line, and may lead to acceleration of the squall line itself.
caption: Airflow in and around a supercell with the inflow at the base on right.
exif: {}